After two delicious seasons of dead ends, red herrings and enough indecipherable clues to send Nancy Drew into early retirement, mysterious texter A was finally "unmAsked" on last night's episode of "Pretty Little Liars." Or was she?

As you'll recall from last week, Officer Garrett was arrested for Ali's murder after Jenna turned in the notorious page five she'd been "safe keeping." Oh, and did we mention she can see now? It looks as though Jenna's eye surgery was a success, but she's keeping that secret between herself and another mysterious party.

The liars got a delivery—four calligraphy-ed invitations to the Junior Society Masquerade Ball (at least A would be benefiting charity when she murders one of them?). Melissa walked in with a big, smug smile on her face, practically singing "I told you so" following the news of Garrett's arrest and Ian's now-presumed innocence. But her cavalier attitude made her appear even more guilty of being A. (Because we know the only person in Rosewoood smart enough to fool Spencer is Melissa, right Hanna?)

Seeking some privacy to hatch out their Masquerade plan, the girls retreated to Ezra's old apartment, which had been vacated after the teacher's unfortunate firing. Following a dream (or was it?!) in which Ali instructed Spencer to take another look at her bag of possessions, Spence once again searched the duffel for clues. She discovered a pen from Dougherty's Landing and information about a Lost Woods Resort near by, leading the liars to take a road trip...

...to the Bates Motel, apparently. Run-down and managed by a creepy fellow who looks like he stores cat livers in jars just for fun, the "resort" supposedly never played host to Vivian Darkbloom (at least that's what Creepy McCreepster said), but the girls checked into Room One anyway. Once he turned in for the night, Spencer and Aria sneaked into the office to check the registry while Emily and Hanna waited in the room. Or at least Hanna did because Emily got a phone call from Maya and went outside to get better reception, which left a showering Hanna susceptible to the hooded figure who tip-toed into the room. But no harm was done as the John/Jane Doe retreated when a phone rang. Team Sparia uncovered the logbook, which revealed Ali had stayed in the room twice—once on the morning before she disappeared and once when she was supposed to be meeting A in Brookhaven. Little did the liars know that throughout their stay at Lost Woods, a peeping Tom watched through a small hole in adjacent Room Two.

Sans dates but in magnificent costumes, the girls all headed to the Masquerade Ball, where they had a midnight drop-dead date. Literally. A warned that one of them would be in a body bag at 12 p.m. if his/her cell phone was not returned. The liars (rather unwisely, if you ask me) decided to split up to cover more ground at the dance. One by one they ran into their loves: Ezra materialized to sweep Aria off her feet and Caleb ditched his mom to hang with Hanna while Paige tracked down Emily to let her know she'd always be there for her. All of which left Spencer alone to go with Mona back to the Lost Woods Resort to investigate (she finally had an epiphany about Room Two).

When Spencer and Mona broke into the room, they made a scary discovery: It was A's command center. Photos and newspaper clippings hung on the walls, with spare doll parts and other odds and ends strewn about the floor. The two also stumbled upon the mock-up for A's masquerade costume: a black swan. Mona told Spencer she'd call and tell Hanna to look out for a feathered lady, but of course she didn't because she's A! Yep, Spencer realized a bit too late, as Mona/A knocked her out and dragged her into the car for a joyride...of death. Spencer finally came to, just in time to silently receive a call from Aria. Mona explained her motives (she wanted revenge for the liars taking her friend Hanna away) and threatened Spencer, telling her she either had to join the A Team or die—all while the liars overheard every dastardly second.

The liars hurried toward Look Out Pass to intercept Mona and Spencer—and just in time because Mona had a gun and she was willing to use it. A tussle ensued, sending Mona flying over a cliff. But she's okay! Don't worry! She'll be spending the better part of her teen years in a psychiatric ward. And, look! Dr. Sullivan's back too. She had been randomly corresponding with Toby. (Does anyone else understand this turn of events? And more importantly, can you explain it to me?) Turns out, A had been threatening Dr. Sullivan's son, and instead of, oh, I don't know, going to the police like any rational adult, she fled. No matter! Spencer and Toby had a lip-locky reunion and everything seemed right with the world for about two minutes. This being Rosewood, the story's far from over.

To wit, when the girls returned home, they were welcomed by another grisly discovery: a body. Maya's body. Poor, Emily. And back in psychiatric lock-down, Mona had a visitor (accomplice?). "I did everything you asked me to," Mona told the mystery guest.

It wasn't over. It still isn't over.

What did you think of "Pretty Little Liars"' grand A reveal? Too expected or was it a shock? Who do you think is working with Mona (she clearly isn't working alone)? Do you think Officer Garrett really killed Ali? And what role does Melissa play in all of this? So many questions to ponder until season three debuts this summer! Tell us all of your thoughts and theories in the comments and on Twitter!